Effect of salt concentration on microbial communities, physicochemical properties and metabolite profile during spontaneous fermentation of Chinese northeast sauerkraut

AIM

The aim of this study was to study the effects of salt concentrations on the microbial communities, physicochemical properties, metabolome profiles and sensory characteristics during the fermentation of traditional northeast sauerkraut.

METHODS AND RESULTS

Northeast sauerkraut was spontaneously fermented under four salt concentrations (0·5, 1·5, 2·5 and 3·5%, w/w). The result of microbiological analysis showed that the population of lactic acid bacteria in 2·5%-salted sauerkraut was significantly higher than that in the other samples. Correspondingly, the speed of decrease in pH and accumulation of acids were the highest in 2·5%-salted sauerkraut. The glucose (analysed by HPLC) in 2·5%-salted sauerkraut was consumed more completely to produce higher levels of organic acids compared to those in the other samples. Principle component analysis showed clear differences in the metabolites of sauerkraut according to different salt concentrations. A higher level of volatiles (detected by HS-SPME/GC-MS) was identified in 2·5%-salted sauerkraut, and sensory evaluation demonstrated that 2·5%-salted sauerkraut had the best sensory characteristics.

CONCLUSION

The best quality of sauerkraut was obtained from fermented under 2·5% salt concentration.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study facilitated the understanding of the effects of salt on the sauerkraut fermentation and may be useful for developing the quality of sauerkraut.

Autophagy inhibitor sensitizes MCF-7 breast cancer cells to novel cyclic tetrapeptide CTS203-induced caspase-9-dependent apoptotic cell death

Histone deacetylase (HDAC) inhibitors have been demonstrated to be effective anti-cancer candidates against aggressive malignancies. In previous study, a novel hydroxamic acid derivate, CTS203 (cyclo(-l-Asu(NHOH)-l-A3mc6c-l-Phe-d-Pro-)), demonstrated promising HDAC inhibitory activity. Herein, more biological evaluations including cell viability, cell cycle distribution, cellular morphology, expression quantification as well as protein-protein interactions were measured to investigate its cytotoxic mechanism. Corresponding with its significant HDAC inhibitory activity, CTS203 led to increased acetylation of H3K14, cell cycle arrest as well as consequent apoptotic cell death, with bearable influence on the viability of normal cells. However, schedule-dependent cytotoxicity against MCF-7 breast cancer cells revealed a delayed cellular response to chemo-stimuli. Within this corresponding period, autophagy was rapidly triggered once exposure started, whereas autophagy inhibitor sensitized MCF-7 cells to CTS203, exhibiting synergistically anti-proliferative effects. The expression variation in MCF-7 cells revealed that the cleavage of Beclin 1 mediated by caspase-8 resulted in disabled autophagy, thus ultimately facilitated and fastened caspase-9-dependent apoptotic cell death. Taken together, these findings elucidated the mechanism of CTS203-induced cytotoxicity as well as suggested that appropriate manipulation of autophagy would be an adjunctive strategy to enhance HDAC inhibitor-induced cell death.

KEYWORDS

cyclic tetrapeptide, apoptosis, autophagy, HDAC inhibitor, Beclin 1 cleavage.

A whole genome scan to map QTL for milk production traits and somatic cell score in Canadian Holstein bulls

The detection and mapping of genetic markers linked to quantitative trait loci (QTL) can be utilized to enhance genetic improvement of livestock populations. With the completion of the bovine genome sequence assembly, single nucleotide polymorphisms (SNP) assays spanning the whole bovine genome and research work on large scale identification, validation and analysis of genotypic variation in cattle has become possible. The objective of the present study was to perform a whole genome scan to identify and map QTL affecting milk production traits and somatic cell scores using linkage disequilibrium (LD) regression and 1536 SNP markers. Three and 18 SNP were found to be associated with only milk yield (MY) at a genome and chromosome wise significance (p < 0.05) level respectively. Among the 21 significant SNP, 16 were in a region reported to have QTL for MY in other dairy cattle populations and while the rest five were new QTL finding. Four SNP out of 21 are significant for the milk production traits (MY, fat yield, protein yield (PY), and milk contents) in the present study. Six and nine SNP were associated with PY at a genome and chromosome wise significant (p < 0.05) level respectively. Three and 17 SNP were found to be associated with FY at a genome and chromosome wise significant (p < 0.05) level. Five and seven SNP were mapped with somatic cell score at a genome and chromosome wise significant (p < 0.05) level respectively. The results of this study have revealed QTL for MY, PY, protein percentage, FY, fat percentage, somatic cell score and persistency of milk in the Canadian dairy cattle population. The chromosome regions identified in this study should be further investigated to potentially identify the causative mutations underlying the QTL.

A whole-genome scan to map quantitative trait loci for conformation and functional traits in Canadian Holstein bulls

Genetic improvement of livestock populations can be achieved through detection and mapping of genetic markers linked to quantitative trait loci (QTL). With the completion of the bovine genome sequence assembly, single nucleotide polymorphism (SNP) assays spanning the whole bovine genome and research work on large-scale identification, validation, and analysis of genotypic variation in cattle has become possible. A total of 462 Canadian Holstein Bulls were used to test the association between SNP and QTL. Single locus linkage disequilibrium regression model was implemented to perform a whole genome scan to identify and map QTL affecting conformation and functional traits. One thousand five hundred thirty-six SNP markers from introns and exons of potential QTL regions for economically important traits across the bovine genome were selected for association analysis. A total of 45 and 151 SNP were found to be associated with 17 conformation and functional traits at a genome- and chromosome-wise significance level, respectively. Among the 196 significant SNP, 169 of them are newly detected in this study, whereas 27 of them have been reported in previous literature and 161 of these were located in genes and are worth further investigating to potentially identify the causative mutations underlying the QTL. The single locus linkage disequilibrium regression method using SNP marker genotypes has proven to be a successful methodology for detecting and mapping QTL in dairy cattle populations.

[Molecular evolution of AdoMet synthetase by DNA recombination with a novel separate-mixing method]

We describe a new approach to in vitro DNA recombination termed Separate-Mixing method in this study. The reaction process of this method consists of two stages: at the first stage the reaction was implemented in two parallel teams, which generated random recombination by template-switching of growing polynucleotides from primers in the presence of unidirectional single-stranded DNA fragments used as templates, and then both teams were mixed together for further extension and recombination of DNA sequences at the second stage. Because of the particular strategy, the reaction process was also accompanied by the other two processes of DNA shuffling and StEP simultaneously. Two AdoMet synthetase genes sam2 from Saccharomyces cerevisiae and metK from Escherichia coli, which have only 56% homology on the DNA level were used for recombination with Separate-Mixing method. DNA recombination was available after a single round of reaction. With sequencing of 10 randomly selected recombinants, no unshuffled parental clone was found, and also no unexpected insertion, deletion or rearrangement was detected. An evolved gene sam' was obtained after screen and selection, which could obviously increase the accumulation of AdoMet in S. cerevisiae.

[A long-term study of a small-caliber arterial autograft used for repair of a large-caliber arterial defect]

OBJECTIVE

The long-term fate of a small arterial graft used to repair a large diameter artery was studied in this study.

METHODS

An end segment of the tail artery (0.3-0.4 mm in diameter) was transplanted to the defect of the carotid artery (1.0-1.4 mm in diameter) in 50 rats. The vessel grafts were examined histologically at 3 weeks and 5, 10 and 12 months after implantation.

RESULTS

At 3 weeks, intimal thickening of the grafts was mild and present only in regions adjacent to the anastomosis. At 5 months, severe intimal thickening was seen along the entire graft wall. At 10 and 12 months, the intimal thickening reduced. Regression of the thickening was uneven within the graft wall. The adventitia thickened at the early postoperative period and reduced at the end of this study. The patency rate of the grafts at 12 months postoperation was 95% (19/20). Angiography indicated that the grafts stopped expanding after 5 months and were only slightly smaller than the recipient arteries at 12 months postoperation.

CONCLUSION

These results suggest that a small, autogenous arterial graft may effectively repair a large-calibre arterial defect.

[Experimental study on revascularization of subdermal vascular network thin flap]

OBJECTIVE

To investigate the survival mechanism of subdermal vascular network thin flap (SVNF).

METHODS

24 rabbits were divided into three groups, in which the SVNF, subdermal vascular network skin graft and the traditional random flap were created respectively. Tissue hyalinization technique was used to find out the differences of vascular architecture between the three groups at the 1st-7th day, and the 14th day postoperatively.

RESULTS

The results showed that the blood supply reestablished earlier in SVNF group than the other two groups.

CONCLUSION

There is a zone of rapid and intensive angiogenesis in the mid-part of SVNF known as "intermediary pedicle". This is the anatomic basis of the early pedicle division and superior survival ratio of SVNF.

[Cardiac metal foreign body: analysis of 21 cases]

OBJECTIVE

To improve early diagnosis and clinical treatment of metal foreign body in the heart.

METHODS

In 21 patients, case history, clinical manifestation, chest X-ray film, and echocardiograph were reviewed. 20 patients received operation: emergency exploration (13) and elective operation (7). Four patients were subjected to cardiopulmonary bypass. The other one was not operated on because of absence of symptoms and small foreign body. Foreign bodies mostly bullets, were usually located in the right ventricle. Ventricular fibrillation occurred in 3 patients during operation, two of them were resuscitated.

RESULTS

20 patients but one recovered, a mortality rate of 5%.

CONCLUSIONS

Early diagnosis, rapid management, and localization of foreign body are essential to the selection of treatment.

[Study on cross-linked capillary columns coated with polyphenylenesiloxane]

A new type of cross-linked capillary column coated with polyphenylenesiloxane which possesses phenylene in the siloxane main chain has been described in this paper. The cross-linking of polyphenylenesiloxane was performed in situ by the induction of DCUP. The structure of polyphenylenesiloxane is as followed: [structure: see text] The repeatabilities and solvent inextractabilities of the column preparations were investigated. For decane and 1-octanol, the values of n/L and k' at 120 degrees C were 2800-3100 and 1.0-1.3, 2400-2800 and 5.0-6.0, respectively. The k' values of the columns scarcely changed after eluting with methylene chloride and pentane. The base-acid property was studied by analyzing 2,6-dimethylphenol and 2,6-dimethylaniline. Besides, in comparision with OV-17 and OV-25, the McReynolds' constants of the cross-linked column were also determined. The advantages of this kind of column are summarized as (1) easy preparation; (2) heat stability improved; and (3) good selectivity for the organic compounds which contain halogen, nitro group or phenol.

[Experimental study on the effects of FGF on the changes in vascular architecture of subdermal vascular plexus of the thin skin flap]

In this experimental study, eight rabbits were used to investigate the survival mechanism of subdermal vascular plexus thin skin flap. By histological, immunohistochemical and microcirculatory observation, we found that the vascular architecture of different parts of the flap had great dissimilarity: the vascular architecture of the proximal part was same as that of normal skin, the middle one showed extremely active angiogenesis, and the distal part also showed angiogenesis but in medium level. We conclude that the middle part of the flap works as an "intermediary pedicle", and is the basis of the early pedicle division and superior survival ratio of the flap. The fibroblast growth factor (FGF) plays an important role in the changes in vascular architecture of the flap.

[Clinical study of the venous flaps]

Seven venous flaps were used clinically. Of them six flaps survived completely, one saphenous venous flap had partial necrosis of the derma. The size of the largest survived flap was 5 cm x 15 cm. Three principles regarding the flap application were emphasized: 1) The tissue surrounding the recipient site should be normal. High venous pressure and oxygen tension in the recipient veins are needed. 2) Rich venous network and an axial vein are required in the recipient site. 3) Reliable fixation of the flap is necessary to avoid any damage to new blood vessels.

[Experimental study of carbohydrate metabolism of venous flaps]

In this experimental study, three sorts of grafts (venous flap, composite graft and axial flap) were created. According to the results of relative contents of LD1, and LD5 in these grafts, the conclusion was drawn: Oxyhemoglobin remaining in the grafts maintained normal carbohydrate metabolism within 24 hours postoperatively. 48 hours later, aerobic oxidation of carbohydrate abated but kept in a considerable level in venous flaps due to the existence of venous blood. 72 hours after the operation, aerobic oxidation of carbohydrate in venous flaps reached its lowest point. At this point, the venous flaps would necrose gradually unless a new nourishing source be obtained. From the 4th postoperative day, aerobic oxidation of carbohydrate of venous flaps began to increase. By the 7th day, aerobic oxidation of carbohydrate of venous flabs returned to normal.

[Experimental study of mechanism of survival of venous flaps]

The mechanism of survival of venous flaps was studied by observations employed in the study of microcirculation and blood vessel perfusion in rabbits. Initially, the flap was nourished by venous blood (within 72 hours): venous blood flowed slowly from the principal vein to its tributary veins, and then through the venous anastomoses (including small venous anastomoses, venular anastomoses and terminal venule anastomoses), reaching other tributary veins. No backflow from venules into capillaries was seen. The second stage was arterial nourishing and vessel reconstructive period (72 hours to 6 weeks): new vessels began to grow into the flaps at 72 hours postoperatively. 4 days postoperation, arterial flow with low velocity appeared in the primary flap arteries and the backflow of venous blood disappeared. 7 days postoperation, the abnormal, flow in 'unphysiologic' channels was replaced by the normal flow in 'physiologic' channels completely. 6 weeks postoperation, the vessel structure of venous flaps was the same as that of normal skin. These results suggested that rich venous network in venous flaps and early invasion of new blood vessels are the mainstay of venous flaps survival.

[Transplantation of a minute artery to bridge over the defect of an artery of significantly larger calibre. An experimental study]

Based on our clinical experience for years of "unequal bite" suturing technique to perform end-to-end anastomosis of vessels with great discrepancy in diameter, the animal experimental study was carried out. An artery defect, 1.0-1.4 mm in diameter, was reunited with, an autogenous arterial graft of 0.3-0.4 mm in diameter. A high patency rate (96% in total) was obtained postoperatively. Histological examination by light microscope and scanning electron microscope showed that the unequal bite suturing technique can produce very smooth anastomotic junction and the minute arterial grafts healed well on a large artery. The unequal bite suturing technique is a very valuable development of the basic end-to-end anastomotic technique. A small autogenous arterial graft may be used to repair defect of an artery with large calibre clinically.